Redundant lumbar nerve root syndrome: myelographic features.

Abstract
Nine patients with redundant lumber nerve root syndrome were identified using positive-contrast myelography, 7 with metrizamide and 2 with iophendylate. Serpiginous intradural filling defects occurred in conjunction with a complete or partial extradural block and spinal stenosis. These redundant nerve roots were seen on the cephalic side of the block. Eight of the 9 patients had pseudoclaudication. One case was found incidentally during a cervical myelogram. This series is presented to demonstrate the characteristic myelographic pattern that should be recognized and differentiated from tortuous intradural blood vessels. Possible causes are discussed.